Switch



Oct. 16, 1923. 1 .1,471,199

, L. A. M. PHELAN SWITCH Filed Aug. 2O 1920 Patented Oct. 16, 1923.

noUIs A. M. PHELAN, or CHICAGO, ILLINOIS.

SWITCH.

Application led August 20, 1920. Serial No. 404,918.

To all whom t may concern.: Be itknown that I, LOUIS A. M. PHELAN, acitizen of the United States of America, and a resident of Chicago,county of Cook, I and State of Illinois, have invented certain new anduseful Improvements in Switches, of which the following is aspecification. My invention relates to electrical switches and it hasspecial reference to electrical contact making devices comprising spacedelectrodes that are sealed into a closed hermetieally sealed containerand are adapted to be brought into electrical (,:ontactingrelation withone another through the agenc o a 16 movable conducting body, prefera lya Huid Suchas mercury, which is also disposed in said container that,upon being tilted, is instrumental in performing the circuit closing andcircuit opening functions between the electrodes and the mercurycomprised in the device.

More particularly my vinvention refers to an electrical contactor deviceof the character indicated which will operate for long periods of timeand' serve to make and break comparatively large amounts of current atcommercial voltagel without undergoing deterioration.

My present invention pertains to an electrical contacter device asdescribed above which, ifdesired, may comprise a cylindrical elongatedtubular member, preferablyv in the form of a hermetically sealed glasscontainer that serves to. house the electrodes and abody of conductingHuid such as mercury, the latter being adapted to bridge the electrodeswithin the tubular member. The tubular member is normally disposed upona suitable supporting structure so that it may be tilted in either oftwo directions and. thus allow the conducting fluid to liow into and outof circuit making and opening positions with the electrodes. Theelectrodes are sealed iii; walls of the tubular member and, as shown inthisparticularin'stance, are adjacent to each other, forming acooperating pair'. A particular object of this invention is to provide=in a contactor devicebi the type above indicated means forsuppressinglor eliminating the arcing and forpreventing deterioration orcorrosion of the contacting parts. i

A further object of this invention isv to provide a particular form ofcontainer for a contacter device of the type indicated which will serveto support'the electrodes in such relation thereto that the walls of thecontainer will not become injured after prolonged use of the device.

A further object is to provide an improved form of electrode for use ina contactor of the type indicated.

A still further object of this invention is to provide a contactordevice of the type indicated that will be simple and economical toconstruct and which will possess a long life even when subjected toconsiderable quantities of electric current and relatively highvoltages.

An illustrative embodiment of the invention is shown in the accompanyingdrawings, in which- Fig. 1 is a front elevation of an assemblage of amercury switch mounted on a tilting lever or holder within a housingreceptacle, the cover of which is removed, and the switch being in itsopen circuit position.

Fig. 2 is a sectional view along the line 2-2 of Fig. 1.l

Fig. 3 is a vertical axial sectional view of the mercury switch in itsopen circuit or horizontal position,

F ig. 4 shows the three fundamental steps in a process of making largecontact-making surface terminals that may be disposed in the glassmercury tube.

Fig. 5 is av vertical axial sectional view of the lower end of themercury switch in an upturned, closed circuit position. The switchproper comprises a hermetically sealed receptacle 1 having a pair ofspaced terminals or electrodes 2 and 3 and a liquid conductor 4 whichonly partly fills the space within the receptacle. The chamber in thereceptacle 1 is free of air but contains an atmosphere of inert gas. Thereceptacle 1 is formed in a manner such that the conductor 4 may make orbreak an electric circuit between said electrodes, thereby closing andopening an external electric `circuit when the receptacle is suitablymoved or tilted. The kwalls of the receptacle 1 are composed ofdielectric material, preferably glass, and comprise an elongatedcylindrical body part 6 made in tubular form with its ends 7 and tightlysealed and provided with Aconductive tera large contact area to themercury 4 or other liquid conductor, and constituting the saidelectrodes 2 and 3. Each of the end caps 9 and 10 is secured to theglass tube by means of a high-grade and durable cement 13, whichpreferably may be com posed of litharge and glycerine. The outer ends otthe conductors 11 and 12 may be secured in place by the application ofsolder 14 at each end of the switch. Both of the electrodes 2 and 3 aredisposed adjacent to one end of the tube 6, so as to be bridged by themercury when the switch is tilted or upcnded, as illustrated in Fig. 5.Said electrodes are both shown as being within the end cap 9.

Furthermore, in order that the electrode 3 may be supported with a fairdegree of rigidity at-or adjacent to the main axis of the switch, thecorresponding end of the tube is formed with an inward tubularpr'ojection 15 and the terminal lead 12 is sealed in the closed innerend thereof at 16. As thus mounted, the electrodes 2 and 3 are disposedin axial alinement concentric with the tube 6 and are equally spacedfrom the walls on all sides. The leading-in wires 11 and 12dprojectexteriorly from the tube at its en s.

The switch unit 1 as aI whole isof a cartridge-like shape and isinterchangeable with similar switches in the supporting structuresubstantially in the manner by which cartridge fuses are mounted. Whenthe switch 1 is placed in service, the end caps 9 and 10 tit intocorresponding spring clips 17 as shown in Figs. l and 2. In one position(Fig. 5) of the switch, the electrodes 2 and 3 are bridged by themercury 4, but when the switch is horizontally positioned (Fig. 3) or isreverscly tilted (Fig. 1, dotted lines) the mercury Hows away from theelectrodes and the external circuit is conse- 4head 36 on the end of thewire.

blocks 26. From thence leads 27 extend to the outside of the casing 20through an aperture 28.

The method' of constructing the switch is in the main as follows: Thetube 6 having been formed and the electrodes 2 and 3 having been securedin place by sealing in the "lass, and the mercury 4 having beensupplied, the tube together with a number of other similar tubes eachprovided with an outstanding tubular stem (not shown), and beingconnected in tree form as understood in the art, are exhausted by meansof a vacuum pump, after which an inert gas may be introduced and thetube sealed, the temporary connection or stem being removed. Thesealing-off tip is shown at 29. The mercury may be inserted eitherbefore or after exhausting the air, preferably before. The inert gasserves to suppress the spark and results in a prolonged life of theterminals.

The electrodes 2 and 3 may be formed as illustrated by the three stepsshown in Fig. 4. To form a terminal I take a piece of suitable wire andfirst form a spiral of helical electrode at one end, as shown at 30. Ithen bend back the straight free end and thread it through the coil, asshown at 31. I then place the coil in a die 32 having a cylindricalcup-like aperture 33 with a central perforation 34 at the bottom for thewire end 35. I then pull the wire end 35 tightly, thereby securelysetting the coil The wire used for the electrodes may be copper or analloy thereof. The leading-in wires 11 and 12 may be composed of adifferent material in order to provide an eiicient seal at the glasscontainer wall and may be brazed to the electrodes 2 and 3. Nickel-ironalloys or the like may be used as leading-in wires and have been foundto provide a satisfactory seal with the glass walls.

The inert gas being preferably under pressure provides a high resistancegap between the velectrodes 2 and 3.

In operation the mercury and gas conduct the heat away from theelectrodes so that excessive concentration of heat is avoided, even onmoderate overloads. Switches of this character, made of glass tubing,have been found to o erate eiiciently under normal working conditions,up to fifteen amperes, though a much smaller current is suf ficient formany uses.

Although but one specific embodiment of this invention has been hereinshown and described, it will be understood that numerous details of theconstruction shown may be altered or omitted without departing from thes irit of this invention as defined by the fo lowing claims.

I claim:

1. An electrical contacter comprising a hermetically'sealed tubularglass container, a pair of spaced electrodes isposed at one end of saidcontainer and between which the electric circuit is adapted to be madeand broken, a leading-in wire fixed to and independently supporting eachof said electrodes, and a body of conductinclr Huid for bridging saidelectrodes at pre etermined times, said leading-in wires extendin to theexterior of said container and seale in the walls thereof, the end ofsaid container furthest from said electrodes being depressed inwardlyand extended in tubular form toward said electrodes, and one of saidleading-in Wires extending through said inwardly depressed end andsealed in the inner end thereof. 2. A11 electrical contactor comprisinga hermetically sealed tubular glass container, a reentrant integraltubular closure at one end of said container extending longitudinallytoward the other end thereof, a pair of spaced electrodes within saidkother end of said container, leading-in wires from said electrodessealed through said container walls, one of said leading-in wiresextending through said reentrant closure, and a pair of metallic capsfitted upon and cemented respectively to the opposite ends of said tubeand electrically connected to said leading-in wires.

3. An electrical contactor comprising a sealed container, a pair ofspaced electrodes within said container, leading-in wires independentlysupporting said electrodes at points spaced from the walls of saidcontainer, and a body of conducting fiuid for bridging said electrodesand for making and breaking a circuit at said electrodes atpredetermined times, said electrodcs being of substantial mass and heatabsorbing capacity and said leading-in wires being sealed in the wallsof said container and possessing a relatively small mass and small heatconducin capacity.

4. n electrlcal contactor comprising an air evacuated herrneticallysealed container, a pair of spaced electrodes of substantial mass withinsaid container, leading-in wires sealed in said container andindependently supporting said electrodes at points spaced from the wallsof said container, said leading-in Wires having a cross-sectional areasmall in respect to that of said electrodes, a body of mercury movablein said container for making and breaking the circuit at saidelectrodes, and an inert gas filling the space in said container notoccupied by said electrodes and mercury.

5. In a device of the character described, an elongated hermeticallysealed receptacle containing a body of mercury, and an electrode membersealed in one of the walls of said receptacle near one end thereof, saidelectrode ,member comprising an enlarged 'said head at which said bodyof mercur serves to break a circuit at redetermine times, said headbeing 'space from the walls of said receptacle, and a relatively thinleading-in wire.

6. A fluid-type contact switch comprising a body of conducting liquid,and an electrode terminal for makin electrical circuit with said body ofcon cting liquid at predetermined times, said terminal comprising a wirehaving an enlargement at the end thereof formed by ceiling a portion ofsaid Wire.

7. A mercury switch comprising a glass tube sealed at its ends, a bodyof mercury in said tube, and current leads sealed in the Walls of saidtube, said leads having tightset coils of wire on their inner ends tocontact with said body of mercury.

8. A mercury electric switch comprising an hermetically sealed casing, abody of mercury therein, electrodes sealed in said casing and eachcomprising a relatively small leading-in portion sealed in the wall ofsaid 'casing and terminating in an enlarged head of large exposedsurface, the said heads being disposed adjacently to and spaced fromeach other and providing large contact-making areasufor said body ofmercury that is adapted to make and break the electric circuit throughthe switch at said enlarged heads.

9. A mercury electric switch comprising an hermetically sealed tubularcontainer, cooperating electrodes sealed in said con tainer which areseverally provided with a relatively small leading-in portion and aterminal head of substantially large contactmaking area, the cooperatingterminal heads being disposed at one end of said container, a body ofmercury movable to and from contact with said terminal heads for makingor breaking a circuit thereat, and an inert gas filling said container.

10. A mercury electric switch comprising an elongated hermeticallysealed glass container, cooperating electrodes sealed in said containernear one end thereof which are severally provided with a terminal headof substantially large contact-making area, a body of mercury movable toand from contact with said terminal heads, and an inert gas filling saidcontainer, one of said electrodes being supported adjacent to itsterminal head by a glass shank extending longitudinally of andintegrally formedwith glass container.

11. An electric switch comprising a tubular glass container, a body ofmercury therein, electrodes disposed in said container, leading-in wiresextending from said electrodes and sealed through the wall of saidcontainer, and terminal heads for said electrodes of substantially largecontact-making area relative to the diameter of and breaking an saidleading-in wires, said body of mercury being movable to and from contactwith said termlnal heads for making or breakmg a circuit thereat.

12. The combination with a pivotally mounted holder having spacedsprlng.. clips, of an electric switch supported in said holder, saidswitch comprising a container, exterior terminals therefor whichremovably engage said spring clips, spaced electrodes sealed in saidcontainer that are connected to said external terminals, and a body ofmercury in said container movable to and from contact with saidelectrodes.

13. The combination with a pivotally A"1,471,1ea y mounted-holder havingspaced electricv terminals thereupon, of an electric switch removablyAengaging said terminals, said switch comprising a sealed container,electrodes disposed therein, exterior terminals embracing said containerand adapted to engage the spaced electric terminals mounted on saidholder, a body of mercury in said container movable to and from contactwith said electrodes, and means for actuating said holder.

9Signed at Chicago this 23 day of June, l 20.

Loms A. M. PHELAN,

